The invention disclosed herein relates to containers, particularly boxes and cartons, for use in packaging various products for shipment. Specifically, this invention concerns packages which telescope, or expand and collapse, to give the container a variable volume depending on the needs of the user. Most boxes and cartons used today have a fixed volume, which often leads to wasted storage space, extra shipping costs, and reduced container strength because the user must employ a container that is too large for volume of the product to be packaged.
To overcome these problems associated with standard containers, various types of telescoping containers have been created to produce variable volumes. This type of container generally consists of two or more portions which may be "telescoped" over one another and fixed in different positions relative to one another before sealing. However, these containers may generally only be fixed at a set number of positions and thus do not have an infinitely variable volume. It would be preferable for the user to be able to use a single container type for a wide range of volumes. In addition, the containers of the prior art had no means of maintaining the telescoping sections relative to one another during filling.
For example, U.S. Pat. No. 3,910,483 to Ritter discloses a container structure formed of two pieces, with the top piece telescoping over the bottom piece to close the container, with the top piece being secured to the bottom piece by adhesive. However, Patent '483 does not disclose a container wherein the top piece may be secured at any location relative to the bottom piece, thereby creating a container of variable volume.
U.S. Pat. No. 4,624,382 to Tontarelli discloses a three-piece plastic container in which each cylindrical piece may be moved relative to the others and secured at set positions to create a variable volume within the container. Patent '382 does not, however, disclose a closed container wherein the telescoping portions may be secured to one another at any position relative to one another, and therefore does not disclose a container with an infinitely variable volume.
U.S. Pat. No. 3,093,291 to Brandle discloses a self-locking telescoping container including a locking means to secure the top piece to the bottom piece. However, this locking means does not allow the pieces to be secured at varying points relative to one another, and thus the Pat. '291 also does not disclose a container of variable volume.